Leer



May 24, 1932. v. MULHOLLAND LEER Original Filed Dec. 27. 1927 [nz/enfofVer YMU//z olla/7d 8% E .gmk

WN N

. jm M QN m N h.. Q

` .WNNMFFIWILLVL Ill e @n AN W Patented May 24, 1932 UNITED STATESPATENT OFFICE VERO-IL MULHOLLAND, OF WEST HARTFORD, CONNECTICUT,ASSIGNORTO HARTFORD- EMPIRE COMPANY, OF HARTFORD, CONNECTICUT, ACORPORATION OF DELAWARE LEER Original application iled December 27,1927, Serial No. 242,877. Divided and this applicatie; mea August 22,1930. Serial No. 477,034.

This invention relates to leers for annealing glassware and moreparticularly to a spe cfic arrangement in a particular type of leer andincorporated with the temperature controlling means thereof,specifically the a-rrangement by which the fiow'of air or othertemperature controlling media in the temperature controlling flues oftheleer are regulated. As such, the invention is a division of mycopending application Serial N o. 242,- 877, filed December 27. 1927,now Patent N o. 1,798,552, issued March 31, 1931.

Leers of the type to which this invention pertains may be in the form oflong tunnel-- like ovens through which the glass may be passed slowlybut continuously upon a suitable carrier, as for example, a belt of wiremesh fabric, suitable means being used to drive the belt.

The temperature inside the tunnel is controlled accurately to providefor the desired temperature gradient in the tunnel and in the ware bythe provision o f one or more longitudinally extending temperaturecontrollingv lues.

In the present instance I have shown flues both above and below thetunnel through which the glassware is passed, butit willbe understoodthat either of theseiiue systems may be used alone or a flue system maybe used solely for carryin a cooling fluid, such as cooling air drawnrom the atmosphere. In the past there have been provided in connectionwith leers of the above described character, passages communicating withthe temperature controllingl iiues at intervals longitudinally lof theirlength by which' air may be drawn in for the-purpose of diluting andcooling the heated gases within the lines, or gases from the lues may bewithdrawn at intervals for the purpose of increasing the temperaturedrop on the downstream side of the withdrawal points, in the case ofheated gases. f

In a similar manner in connection with fiues used solely for cooling,portions of the cooling'air havebeen drawn ofi' at intervals, so thatthe remaining air in t-he iiues will have a decreasing cooling effect,which mayy be useful in connectlon with the Hue. carry` ing cooling airin a direction opposite to that of the movement of the ware.

Among .the objects of the present invention are to provide in connectionwith a leer of the above described character a substantially constantrate of cooling of the ware by controlling the iow through the severalpassages communicating with the tempera.

ture controlling iues in such a manner that substantially the samedamper settings at each of the passages will give the desired results,thus roviding for operation and conrgl of the eer by comparativelyunskilled a or.

In practice, this object may be achieved eitherV by'the provision ofpassages atl progressively decreasing distance apart lon tudinally ofthe leer communicating with t temperature controlling flues, or byroviding the passages with progressively lncreasing effective crosssectional areas toward the one end (usually the exit end) of the leer,or by a combination of these two methods.

Other objects and advantages of my in vention will appear from ythefollowing specification and sub-joined claims when taken in connectiondrawings, in which: v

Figure 1 is a diagrammatic' vertical longitudinal sectional view of theforward half of a leer embodying my invention;

Fig. 2 is a similar View of the rear half of the leer shown in Fig. 1;

Fig. 3 is a section taken substantiallyon the l1ne33 in Fig. 1;v

Fig. 4 is a section taken substantially on the broken line 4-4 in Fig.1; v

Fig. 5 is a section taken substantially on the broken line 5 -5 in FigFig. 6 is a section taken substantially on the line 6 6 in Fig.'2;

Fig. 7 is an elevation of one of the damper members for admittingamospheric air to the lower iiues having relatively small openings forair admission; f

Fig. 8 is an elevation of a damper member having larger openings; and

Fig. 9 is a section on the line 9-'9 of Fi 7 and 8 showing the'conguiation of t e damper members.

with the accompanying Referring to the drawings', the leer tunnel l maybe constructed of a plurality of substantially interchangeable sections2 arranged in end to end relation and suitably Supported in any desiredmanner, as for example. the manner shown in my prior Patent 1,560,481,granted Nov. 3, 1925. The Ware may be carried through. the leer in anysuitable manner, as for example, upon a flexible wire belt 3 which maybe driven by suitable mechanism (not shown), this mechanism preferablybeing of the type shown in my prior patent above referred to. Heatingues 4 and 5 extend longitudinally beneath the forward and rear portionsof the tunnel respectively and communicate through a passageway 6 with acommon fire b0x7 disposed beneath the leer at a point spaced from theentrance end of the tunnel. The damper 8 controls the passage of theheating media through the flue 4 from the fire boxL 7, and thea damper 9the passage of the heating media through flue 5, thus providing forindependent regulation of the drafts in these flues. The fire box 7 maybe provided with one or more suitable burners 10 for' oil, gas or otherfuel which may be directed thereinto through the opening 11, air tosupport combustion entering the fire box through the annular spacebetween the burner 10 and the sides of the opening 11. A desired amountof diluting air may beadmitted to the fire box 7 through the passage 12,this amount being controlled by a'suitable damper 13. By suitableregulation of the burner 10 and the dampers 13, 8 and 9, the temperatureand volume of the heating gases passing along the ues 4 and 5respectively, may be controlled. It is usually desirable to control thetemperature of the gasespassing from the fire box into filles throughthe passage 6 within narrow limits, and by suitable control of theamounts and velocity of gases passing along the ues 4 and 5, thetemperature drop along these flues may be varied at will, as the heatloss through the insulation 14 from the flue 4, and the forward portionof the flue 5, will not vary materially with a change in the velocity ofthe gases passing therethrough. The ue 4 is provided with an outletpassage 15 adjacent to the receiving end of the tunnel, which passagecommunicates with passages 16, one on each side of the tunnel, leadingto header 17, which in turn communicates through the ducts 18 and 19with the suction device 20, here shown as a motor driven fan. v

In order to control the temperature gradient in the tunnel 1 by coolingthe gases in the Hue 5, I provide a plurality of dampered air inletpassages 21 which are spaced apart unequal distances, as seen in Fig. 2,the distances being progressively less toward the discharge end of theleer. Instead of this progressive change in the spacing of the passages,or in addition thereto, the effective area of these passages 21 may beprogressively greater toward the discharge end of the leer, whereby witha' given damper setting,

that is, with the dampers in all of the passages 21 opened at a certaingiven angle, in-

creasing amounts of cooling air will be a imitted per unit length of thetunnel. In

practice a convenientway of accomplishing this variation using similarvparts for economy in manufacture is to provide damper members withprogressively greater openings, but all cooperable with ports of thesame size. I prefer to construct the dampers from cylindrical bars andhaving cut out segmentsto permit the passage of air when the bars arerotated to the proper positions. Such bars are shown in Figs. 7, 8 and 9at 21a and 21b respectively and are provided with cut out segments 21 ofvarying length so that the bar 21a may, for example, be provided withfour cut out portions or segments each of two inches length thusproviding an aggregate length of eight inches,

while the bar 21b may be provided with two cut out segments each offifteen inches, or an aggregate length of thirty inches. I plan to-usebars having progressively increasing total or aggregate cut out lengthsor openings' toward the exit end of the leer for ac complishing thevaforesaid objects. The reason for this is that it requires less coolingair to cool the gases a given number of degrees at a point where theyare hotter and their total volume is less than where they are cooler,and the size and disposition of these inlets is such at with the dampersset at a certain angle, the temperature drop per unit length of tunnelwill be constant, so that the rate of cooling of the ware in the tunnelwill be substantially constant. `This is an important feature, as leersof this character are usually operated by relatively unskilled labor,and in order to have proper operation with dampers and passages ofuniform size and spacing, different damper settings would be requiredwhich would require the services of a skilled operator.

.The flue 5 communicates through an inclined passage 22 with a header23, communicating in turn with passages 24, one-on each side of thetunnel 1, which lead to a top header or wind box 25 communicating withthe fan 20. Thus it will be seen that iiues 4 and 5 are at all timesmaintained at subatmospheric pressure, whereby any leaks in these flues,as for example, in the joints between contiguous sections 2, will notpermit the combustion products -to impinge upon the ware or cause hotspots inthe tunnel, but will only serve to withdraw slight amounts ofair from the tunnel which has no harmful efect. .v

The portion 26 formed as a prolongation of the iue 5 to the right of theinclined passage 22 (as seen in Fig. 2) is used toaccelcrate the coolingof the -ware and is provided with a dampered air inlet passage 27adjacent to the discharge end of the leer, cold air from the atmosphereflowing through the passage 27 and to the passage 22 countercurrent tothe direction of motion of the ware.

Flues 2 8 and 29 extend longitudinally above the tunnel l and preferablyhave acommon Wall with a roof of said tunnel in the same manner thatflues 4 and 5 have a common wall with the floor of the tunnel. Aspecially de signed fire box 30 is interposed between the filles 28 and29 and has a common wall 31 with the top of the tunnel. Fire box 30 isprovided with a plurality of burners 31 syn1- metrically disposed withrespect thereto, preferably three on each side, these burners beingdirected into openings 32, similar te the opening 11 in fire box 7 andhaving annular spaces as described above to provide for the entrance ofprimary air to support combustion. Openings 33 controlled by dampers 34are provided, preferably one for each of the burners 31 for the purposeof admitting controllable amounts of secondary and diluting air, thecontrol beingsimilar to that described above in connection with thelower fire box 7.

The flue 28 is provided with one or more outlet openings 35, two beingshown, which are controlled by suitable dampers 36 and which communicatethrough header 17 and conduits 18 and 19 with the fan 20.

Flue 29 may be provided with a. plurallty of dampered air inlet openings37, two of which are. shown, for the same purpose dcscribed above inconnection with air inlet openings 21. This flue is separated by asuitable dividing wall 38 from a cooling flue 39, to be described.` Theheating media are drawn off from the l'lue 29 by one or more suitablepassages 40 controlled by dampers 41, the passages 40 communicatingthrough the conduit 19 with the suction fan 20. Thus it Willbe seen thatthe draft through flues 28 and 29 is controlled respectively by dampers.3G and 41 in a manner similar to that in which the draft throughlues 4and 5 is controlled by dampers 8 and 9 respectively. The Hue 39 isformed as a prolongation of the l'lue 29 at the cooler end portion ofthe leer for accelerating the cooling of the ware, and is open to theatmosphere at the exit end of the leer as shown at 42. The Hue 39communicates with the conduit 19 through a plurality of spaced dampere'dair outlet passages 43 by which the amount of cooling air drawn in adirection counter-current to that of the movement of theV ware throughthe flue 29, and the distance which it passes may be controlled.

When used as a decorating leer, the glassware entering the left handend, as seen in Fig. 1, is at substantially room temperature and isheated at a safe rate by transmitted and radiated heat, and to a lesserextent by convection currents, from the llues 4 and 28 in which thegases flow in a direction countercurrent to the Ware, so that by thetime the Ware reachesa point substantially above the passageway 6, ithas been brought almost to the fusing temperature of the decoratingmaterial or the flux used therewith. In thenext zone to the front edgeof the lire box 30, the ware will be maintained at a substantiallyconstant temperature,- due Vto the fact that the gases in the lues 5 and28 are traveling in opposite directions, and thus each tends to balancethe temperature drop Vin the other. In the next zone, that is,immediately under the furnace 30, which is of substantial longitudinalextent and which is of substantially Vthe same width as the tunnel, theware will be maintained again at a substantially con- Stant temperaturewhich may be maintained slightly higher than the temperature in the.preceding rane. During the passage through these two zones, the fusionof the decorating material onto the ware takes place. It is necessary toprovide a material time for this fusion to take place as well as acertain temperature, so that the offset position of fire boxes7 and 30and the longitudinal extent of fire box 30 are both of prime importance.The heating eii'ect on the ware by fire box 30 is still furtheraugmented by the fact that this fire box has a common wall with the roofof the tunnel for substantially its entire length and breadth, and theburners 31 therein are symmetrically disposed with respect to the firebox, so that a contant temperature may be maintained.

In fusing the decoration on certain types of ware, namely that type inwhich the decoration is all adjacent to the top of the articles and inwhich the articles are relatively light it is sometimes desirable toheat the top decorated portion hotter than the bottom, so as to maturethe decoration without the possibility of heating thebottom portion toan extent likely to cause, deformation thereof. The particular type offire box 30 and its individual control, apart from-that ,of the fire box7, is especially adapted for this purpose.

After the color has been matured on the Ware, either with or Withoutdifferential heating as described above, it must be annealed to take outany strains which may have been introduced and to prevent theintroduction of new strains. and for this purpose a material length orzonein the tunnel is provided, namely that shown in Fig. 1 to the rightof the lire box 30. in which zone" there are no passages to the fines 5and 29 for the entrance of cooling air, but the temperature is regulatedby thevelocity control described above and by the decreasing thicknessofthe insulation 14. The succeeding zone of the tunnel which may be saidto be that portion shown at the left in Fig. 2 to a point near thepartition 38 between the Hues 29 and 39, vconstitutes a retarded coolingzone in -which the ware is slowly'cooled Ato approximately the lowerannealing temperature? or the temperature below which permanent strainscannotbe reintroduced into the ware ,even though it is cooled veryrapidly. During its passage from a position under the tire box 30 toapproximately the end of this last mentioned zone, the normal rate ofcooling of the ware is retarded to permit the permanent strains to workthemselves out of the ware and to permit it to be cooled to a pointbelow which they will not be reintroduced.

The cooling below this temperature may be carried on at a relativelyrapid' rate. The annealing and cooling portions of the leer to theright, as seen in Figs. 1 and 2 of the fire box 30, are preferablyregulated so that all portions of the leer in any t1 ansversesectionwill be maintained at a substantially constant temperature, thus tendingto remove any strainswhich have been previously introduced bydifferential heating-or in any other manner. Accelerated cooling takesplace in the succeeding zones, too rapid cooling being prevented in thefirst part of these zones by carrying the lower Hue 5 to a point nearerthe discharge end of the leer than the upper heating Hue 29 anddepending upon hot convection currents rising from the hot lower Hue andcool currents moving 4downward from the cooler upper Hue 39 to governthe rate of cooling of the ware. The final cooling immediately adjacentto the discharge end of the tunnel may be further accelerated byproviding the Acounter-current cold air Hue 26 in addition to thecooling effect of the top Hues 39.

The leer tunnel used for decorating purposes may well be longer than inthe ordinary -annealingdeen such as is shown in my prior patent abovereferred to, so as to provide the necessary space and time for heatinthe ware from room temperature to the usion temperature of thedecorating material and for maintaining it at the high fusiontemperature before the annealing is started.

It should be noted that the top Hues 28, 29

and 39 are all connected with the single suction device 20 and aremaintained at subatmospheric pressure for the reasons described above inconnection with the lower Hues 4 and 5.

While I have shown and described but one embodiment of my invention, itis to-be understood that many changes might be made therein, anddescribed might be used in other connectionsand I do not wish,therefore, to be limited except by the scope`of the appended claims,which are to be construed as broadly as the prior art permits.

and many of the ldetails herein shown I claim as my invention:

1. A -leer comprising an elongate tunnel, means for moving articles ofglassware therethrough, a longitudinally extending temperaturecontrolling Hue associated with said tunnel and communicating at one endwith a.

source of temperature controlling media, a plurality of damperedpassages communicating with said Hue and disposed at intervalstherealong, said passages being progressively closer together along thelength of said Hue, whereby the temperature gradient in the warecontrolled by said Hue may be maintained constant per unit of length ofthe leer' with the same damper settings at each of said passages. v

2.` A leer comprising an elongate tunnel, means for moving articles ofglassware therethrough, a longitudinal heating Hue associated with saidtunnel, means for supplying hot gases thereto, a plurality of damperedair inlet openings disposed at intervals along said Hue, and means forwithdrawing the gases from the cooler end of said Hue, the dispositionof `the air, inlet openings being such that increasingA amounts of airwill be admitted toward the cooler end of said Hue per unit of length,whereby the temperature drop in the Hue may be maintained constant perunit of length with the same damper settings at each of saidair inletopenings.

3. A leer, comprising an elongate tunnel, means for moving articles ofglassware therethrough, a longitudinally extending temperaturecontrolling Hue associated with said tunnel and communicating at one endwith I passages 4. leer comprising an elongate tunnel,

ymeans for moving articles of glassware therethrou h, a longitudinalheating Hue associated vith said tunnel, means for supplying hot gasesthereto, a pluralityof dampered air inlet openings disposed at intervalsalong said Hue, and means for withdrawing the -gases from the Acoolerend' of said Hue, the

sizes of said air inlet openings being progressively increased so thatincreasing amounts of air will be admitted toward the cooler end of saidHue per unit of length, whereby the temperature drop in the Hue may bemaintained constant per unit of length with the same damper settings ateach of said air inlet openings.

5. A leer comprising an elongate tunnel,

of dampered passages communi-l means for moving articles of glasswarethere. through, a longitudinally extending temperature controlling Hueassociated with said ltunnel and communicating at one end with a sourceof temperature controlling media, a plurality of dampered passagescommunicating with said Hue at intervals along its length, the saidpassages being progressively closer together from` one end of said Hueto the other and having progressively increasing cross sectional areas,and means for causing a How of temperature controlling media throughsaid Hue and said passages, whereby the temperature gradient of the'warecontrolled by said Hue may be maintained substantially constant the unitof length of the leer by the same damper settings at each of saidpassages.

6. A leer comprising an elongate tunnel, means for moving articles ofglassware therethrough, a longitudinal heating Hue associated with saidtunnel, means for supplying hot gases thereto, a plurality of damperedair inlet openings disposed at intervals along said Hue, and means forwithdrawing the gases from the cooler end of said Hue, the dispositionand sizes of said air inlet openings being such that increasing amountsof air will be admitted toward the cooler end of said Hue per unit oflength, whereby the temperature drop in the Hue may be maintainedconstant per unit of length with the same damper settings at each ofsaid air inlet open- 1n s. Lligned at Hartford, Connecticut, this 19th 4day of August, 1930.

VERGIL MULHOLLAND.

